The "good" ones have a larger viewing area and they have four arc sensors vs two in the cheapies.
I went with the HF, but I check the cleanliness of the outside frequently. If you are stick welding, and both sensors get dirtied, the lens might not darken.
If you have four sensors, the chance of all four getting smudged at the same time is pretty slim.
I watched a guy at a production shop welding pieces of a RR car.
He had a $500 helmet. The only time he ever flipped it up was at break time.
